Apparatus and method for treating aqueous solutions and contaminants therein

ABSTRACT

The present disclosure is generally directed to devices and methods of treating aqueous solutions to help remove or otherwise reduce levels, concentrations or amounts of one or more contaminants. The present disclosure relates to a system and apparatus which is adapted to receive components including at least one counterelectrode (e.g. cathode) and at least one photoelectrode (e.g. anode) provided or arranged around at least one UV light source, and/or receive, contain and/or circulate fluid or aqueous solution.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority as a continuation application to U.S.patent application Ser. No. 14/177,314 filed Feb. 11, 2014, which claimspriority to and benefit of U.S. Provisional Patent Application Ser. No.61/763,336 filed Feb. 11, 2013, U.S. Provisional Patent Application Ser.No. 61/782,969 filed Mar. 14, 2013, U.S. Provisional Patent ApplicationSer. No. 61/812,990 filed Apr. 17, 2013, and U.S. Provisional PatentApplication Ser. No. 61/930,337 filed Jan. 22, 2014, each of which ishereby incorporated herein by reference in its entirety.

BACKGROUND

Aqueous solutions often contain one or more contaminants. Such aqueoussolutions include, but are not limited to, hydraulic fracturing fluid,hydraulic fracturing backflow water, high-salinity solutions,groundwater, seawater, wastewater, drinking water, aquaculture (e.g.,aquarium water and aquaculture water), ballast water, and textileindustry dye wastewater. Further information on example aqueoussolutions follows.

Hydraulic fracturing fluid includes any fluid or solution utilized tostimulate or produce gas or petroleum, or any such fluid or solutionafter it is used for that purpose.

Groundwater includes water that occurs below the surface of the Earth,where it occupies spaces in soils or geologic strata. Groundwater mayinclude water that supplies aquifers, wells and springs.

Wastewater may be any water that has been adversely affected in qualityby effects, processes, and/or materials derived from human or non-humanactivities. For example, wastewater may be water used for washing,flushing, or in a manufacturing process, that contains waste products.Wastewater may further be sewage that is contaminated by feces, urine,bodily fluids and/or other domestic, municipal or industrial liquidwaste products that is disposed of (e.g., via a pipe, sewer, or similarstructure or infrastructure or via a cesspool emptier). Wastewater mayoriginate from blackwater, cesspit leakage, septic tanks, sewagetreatment, washing water (also referred to as “graywater”), rainfall,groundwater infiltrated into sewage, surplus manufactured liquids, roaddrainage, industrial site drainage, and storm drains, for example.

Drinking water includes water intended for supply, for example, tohouseholds, commerce and/or industry. Drinking water may include waterdrawn directly from a tap or faucet. Drinking water may further includesources of drinking water supplies such as, for example, surface waterand groundwater.

Aquarium water includes, for example, freshwater, seawater, andsaltwater used in water-filled enclosures in which fish or other aquaticplants and animals are kept or intended to be kept. Aquarium water mayoriginate from aquariums of any size such as small home aquariums up tolarge aquariums (e.g., aquariums holding thousands to hundreds ofthousands of gallons of water).

Aquaculture water is water used in the cultivation of aquatic organisms.Aquaculture water includes, for example, freshwater, seawater, andsaltwater used in the cultivation of aquatic organisms.

Ballast water includes water, such as freshwater and seawater, held intanks and cargo holds of ships to increase the stability andmaneuverability during transit. Ballast water may also contain exoticspecies, alien species, invasive species, and/or nonindiginous speciesof organisms and plants, as well as sediments and contaminants.

A contaminant may be, for example, an organism, an organic chemical, aninorganic chemical, and/or combinations thereof. More specifically,“contaminant” may refer to any compound that is not naturally found inan aqueous solution. Contaminants may also include microorganisms thatmay be naturally found in an aqueous solution and may be considered safeat certain levels, but may present problems (e.g., disease and/or otherhealth problems) at different levels. In other cases (e.g., in the caseof ballast water), contaminants also include microorganisms that may benaturally found in the ballast water at its point of origin, but may beconsidered non-native or exotic species. Moreover, governmental agenciessuch as the United States Environmental Protection Agency, haveestablished standards for contaminants in water.

A contaminant may include a material commonly found in hydraulicfracturing fluid before or after use. For example, the contaminant maybe one or more of the following or combinations thereof: diluted acid(e.g., hydrochloric acid), a friction reducer (e.g., polyacrylamide), anantimicrobial agent (e.g., glutaraldehyde, ethanol, and/or methanol),scale inhibitor (e.g., ethylene glycol, alcohol, and sodium hydroxide),sodium and calcium salts, barium, oil, strontium, iron, heavy metals,soap, bacteria, etc. A contaminant may include a polymer to thicken orincrease viscosity to improve recovery of oil. A contaminant may alsoinclude guar or guar gum, which is commonly used as a thickening agentin many applications in oil recovery, the energy field, and the foodindustry.

A contaminant may be an organism or a microorganism. The microorganismmay be for example, a prokaryote, a eukaryote, and/or a virus. Theprokaryote may be, for example, pathogenic prokaryotes and fecalcoliform bacteria. Example prokaryotes may be Escherichia, Brucella,Legionella, sulfate reducing bacteria, acid producing bacteria, Cholerabacteria, and combinations thereof.

Example eukaryotes may be a protist, a fungus, or an algae. Exampleprotists (protozoans) may be Giardia, Cryptosporidium, and combinationsthereof. A eukaryote may also be a pathogenic eukaryote. Alsocontemplated within the disclosure are cysts of cyst-forming eukaryotessuch as, for example, Giardia.

A eukaryote may also include one or more disease vectors. A “diseasevector” refers any agent (person, animal or microorganism) that carriesand transmits an infectious pathogen into another living organism.Examples include, but are not limited to, an insect, nematode, or otherorganism that transmits an infectious agent. The life cycle of someinvertebrates such as, for example, insects, includes time spent inwater. Female mosquitoes, for example, lay their eggs in water. Otherinvertebrates such as, for example, nematodes, may deposit eggs inaqueous solutions. Cysts of invertebrates may also contaminate aqueousenvironments. Treatment of aqueous solutions in which a vector (e.g.,disease vector) may reside may thus serve as a control mechanism forboth the disease vector and the infectious agent.

A contaminant may be a virus. Example viruses may include a waterbornevirus such as, for example, enteric viruses, hepatitis A virus,hepatitis E virus, rotavirus, and MS2 coliphage, adenovirus, andnorovirus.

A contaminant may include an organic chemical. The organic chemical maybe any carbon-containing substance according to its ordinary meaning.The organic chemical may be, for example, chemical compounds,pharmaceuticals, over-the-counter drugs, dyes, agricultural pollutants,industrial pollutants, proteins, endocrine disruptors, fuel oxygenates,and/or personal care products. Examples of organic chemicals may includeacetone, acid blue 9, acid yellow 23, acrylamide, alachlor, atrazine,benzene, benzo(a)pyrene, bromodichloromethane, carbofuran, carbontetrachloride, chlorobenzene, chlorodane, chloroform, chloromethane,2,4-dichlorophenoxyacetic acid, dalapon, 1,2-dibromo-3-chloropropane,o-dichlorobenzene, p-dichlorobenzene, 1,2-dichloroethane,1,1-dichloroethylene, cis-1,2-dichloroethylene,trans-1,2-dichloroethylene, dichlormethane, 1,2-dichloropropane,di(2-ethylhexyl) adipate, di(2-ethylhexyl) phthalate, dinoseb, dioxin(2,3,7,8-TCDD), diquat, endothall, endrin, epichlorohydrin,ethylbenzene, ethylene dibromide, glyphosate, a haloacetic acid,heptachlor, heptachlor epoxide, hexachlorobenzene,hexachlorocyclopentadiene, lindane, methyl-tertiary-butyl ether,methyoxychlor, napthoxamyl (vydate), naphthalene, pentachlorophenol,phenol, picloram, isopropylbenzene, N-butylbenzene, N-propylbenzene,Sec-butylbenzene, polychlorinated biphenyls (PCBs), simazine, sodiumphenoxyacetic acid, styrene, tetrachloroethylene, toluene, toxaphene,2,4,5-TP (silvex), 1,2,4-trichlorobenzene, 1,1,1-trichloroethane,1,1,2-trichloroethane, trichloroethylene, a trihalomethane,1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, vinyl chloride,o-xylene, m-xylene, p-xylene, an endocrine disruptor, a G-series nerveagent, a V-series nerve agent, bisphenol-A, bovine serum albumin,carbamazepine, cortisol, estradiol-17β, gasoline, gelbstoff, triclosan,ricin, a polybrominated diphenyl ether, a polychlorinated diphenylether, and a polychlorinated biphenyl. Methyl tert-butyl ether (alsoknown as, methyl tertiary-butyl ether) is a particularly applicableorganic chemical contaminant.

A contaminant may include an inorganic chemical. More specifically, thecontaminant may be a nitrogen-containing inorganic chemical such as, forexample, ammonia (NH₃) or ammonium (NH₄). Contaminants may includenon-nitrogen-containing inorganic chemicals such as, for example,aluminum, antimony, arsenic, asbestos, barium, beryllium, bromate,cadmium, chloramine, chlorine, chlorine dioxide, chlorite, chromium,copper, cyanide, fluoride, iron, lead, manganese, mercury, nickel,nitrate, nitrite, selenium, silver, sodium, sulfate, thallium, and/orzinc.

A contaminant may include a radionuclide. Radioactive contamination maybe the result of a spill or accident during the production or use ofradionuclides (radioisotopes). Example radionuclides include, but arenot limited to, an alpha photon emitter, a beta photon emitter, radium226, radium 228, and uranium.

Various methods exist for handling contaminants and contaminated aqueoussolutions. Generally, for example, contaminants may be contained toprevent them from migrating from their source, removed, and immobilizedor detoxified.

Another method for handling contaminants and contaminated aqueoussolutions is to treat the aqueous solution at its point-of-use.Point-of-use water treatment refers to a variety of different watertreatment methods (physical, chemical and biological) for improvingwater quality for an intended use such as, for example, drinking,bathing, washing, irrigation, etc., at the point of consumption insteadof at a centralized location. Point-of-use treatment may include watertreatment at a more decentralized level such as a small community or ata household. A drastic alternative is to abandon use of the contaminatedaqueous solutions and use an alternative source.

Other methods for handling contaminants and contaminated aqueoussolutions are used for removing gasoline and fuel contaminants, andparticularly the gasoline additive, MTBE. These methods include, forexample, phytoremediation, soil vapor extraction, multiphase extraction,air sparging, membranes (reverse osmosis), and other technologies. Inaddition to high cost, some of these alternative remediationtechnologies result in the formation of other contaminants atconcentrations higher than their recommended limits. For example, mostoxidation methods of MTBE result in the formation of bromate ions higherthan its recommended limit of 10 μg/L in drinking water (Liang et al.,“Oxidation of MTBE by ozone and peroxone processes,” J. Am. Water WorksAssoc. 91:104 (1999)).

A number of technologies have proven useful in reducing MTBEcontamination, including photocatalytic degradation with UV light andtitanium dioxide (Barreto et al., “Photocatalytic degradation of methyltert-butyl ether in TiO₂ slurries: a proposed reaction scheme,” WaterRes. 29:1243-1248 (1995); Cater et al., UV/H₂O₂ treatment of MTBE incontaminated water,” Environ. Sci Technol. 34:659 (2000)), oxidationwith UV and hydrogen peroxide (Chang and Young, “Kinetics of MTBEdegradation and by-product formation during UV/hydrogen peroxide watertreatment,” Water Res. 34:2223 (2000); Stefan et al., Degradationpathways during the treatment of MTBE by the UV/H₂O₂ process,” Environ.Sci. Technol. 34:650 (2000)), oxidation by ozone and peroxone (Liang etal., “Oxidation of MTBE by ozone and peroxone processes,” J. Am. WaterWorks Assoc. 91:104 (1999)) and in situ and ex situ bioremediation(Bradley et al., “Aerobic mineralization of MTBE and tert-Butyl alcoholby stream bed sediment microorganisms,” Environ. Sci. Technol.33:1877-1879 (1999)).

Use of titanium dioxide (titania, TiO₂) as a photocatalyst has beenshown to degrade a wide range of organic pollutants in water, includinghalogenated and aromatic hydrocarbons, nitrogen-containing heterocycliccompounds, hydrogen sulfide, surfactants, herbicides, and metalcomplexes (Matthews, “Photo-oxidation of organic material in aqueoussuspensions of titanium dioxide,” Water Res. 220:569 (1986); Matthews,“Kinetic of photocatalytic oxidation of organic solutions overtitanium-dioxide,” J. Catal. 113:549 (1987); Ollis et al., “Destructionof water contaminants,” Environ. Sci. Technol. 25:1522 (1991)).

Irradiation of a semiconductor photocatalyst, such as titanium dioxide(TiO₂), zinc oxide, or cadmium sulfide, with light energy equal to orgreater than the band gap energy (Ebg) causes electrons to shift fromthe valence band to the conduction band. If the ambient and surfaceconditions are correct, the excited electron and hole pair canparticipate in oxidation-reduction reactions. The oxygen acts as anelectron acceptor and forms hydrogen peroxide. The electron donors(i.e., contaminants) are oxidized either directly by valence band holesor indirectly by hydroxyl radicals (Hoffman et al., “Photocatalyticproduction of H₂O₂ and organic peroxide on quantum-sized semi-conductorcolloids,” Environ. Sci. Technol. 28:776 (1994)). Additionally, etherscan be degraded oxidatively using a photocatalyst such as TiO₂ (Lichtinet al., “Photopromoted titanium oxide-catalyzed oxidative decompositionof organic pollutants in water and in the vapor phase,” Water Pollut.Res. J. Can. 27:203 (1992)). A reaction scheme for photocatalyticallydestroying MTBE using UV and TiO₂ has been proposed, butphotodegradation took place only in the presence of catalyst, oxygen,and near UV irradiation and MTBE was converted to several intermediates(tertiary-butyl formate, tertiary-butyl alcohol, acetone, andalpha-hydroperoxy MTBE) before complete mineralization (Barreto et al.“Photocatalytic degradation of methyl tert-butyl ether in TiO₂ slurries:a proposed reaction scheme,” Water Res. 29:1243-1248 (1995)).

A more commonly used method of treating aqueous solutions fordisinfection of microorganisms is chemically treating the solution withchlorine. Disinfection with chlorine, however, has severaldisadvantages. For example, chlorine content must be regularlymonitored, formation of undesirable carcinogenic by-products may occur,chlorine has an unpleasant odor and taste, and chlorine requires thestorage of water in a holding tank for a specific time period.

Aqueous solutions used for hydraulically fracturing gas wells (e.g.,fracturing or frac fluids) or otherwise stimulating petroleum, oiland/or gas production also require treatment. Such solutions or fracfluids typically include one or more components or contaminantsincluding, by way of example and without limitation, water, sand,diluted acid (e.g., hydrochloric acid), one or more polymers or frictionreducers (e.g., polyacrylamide), one or more antimicrobial agents (e.g.,glutaraldehyde, ethanol, and/or methanol), one or more scale inhibitors(e.g., ethylene glycol, alcohol, and sodium hydroxide), and one or morethickening agents (e.g., guar). In addition, a significant percentage ofsuch solutions and fluids return toward the Earth surface as flowback,and later as produced water, after they have been injected into ahydrofrac zone underground. As they return toward the Earth surface, thesolutions and fluids also pick up other contaminants from the earth suchas salt (e.g., sodium and calcium salts). Such fluids may also includebarium, oil, strontium, iron, heavy metals, soap, high concentrations ofbacteria including acid producing and sulfate reducing bacteria, etc.

Aqueous solutions used for hydraulically fracturing gas wells orotherwise stimulating oil and gas production are difficult and expensiveto treat for many reasons including, without limitation, the salinity ofthe solutions. For that reason, such fluids are often ultimatelydisposed of underground, offsite, or into natural water bodies. In somecases, certain states and countries will not allow fracking due toremediation concerns.

Accordingly, there is a need in the art for alternative approaches fortreating aqueous solutions to remove and/or reduce amounts ofcontaminants. Specifically, it would be advantageous to have apparatusand/or methods for treating various aqueous solutions includinghydraulic fracturing fluid, hydraulic fracturing backflow water,high-salinity water, groundwater, seawater, wastewater, drinking water,aquarium water, and aquaculture water, and/or for preparation ofultrapure water for laboratory use and remediation of textile industrydye wastewater, among others, that help remove or eliminate contaminantswithout the addition of chemical constituents, the production ofpotentially hazardous by-products, or the need for long-term storage.

SUMMARY

The present disclosure is generally directed to devices and methods oftreating aqueous solutions to help remove or otherwise reduce levels oramounts of one or more contaminants. More specifically, the presentdisclosure relates to an assembly for removing or reducing the level ofcontaminants in a solution comprising: a first light source having alongitudinal axis; a plurality of second light sources provided about aline concentric to the longitudinal axis of the first light source; afirst photoelectrode provided between the first light source andplurality of second light sources; a second photoelectrode providedaround the second light sources; at least one counterelectrode providedbetween the first photoelectrode and the second photoelectrode; whereinthe first photoelectrode and second photoelectrode each comprise aprimarily titanium foil support with a layer of titanium dioxideprovided on at least one surface the photoelectrode; and wherein thefirst photoelectrode, second photoelectrode and at least onecounterelectrode are each coupled to a respective terminal adapted to beelectrically coupled to a power supply.

The present disclosure further relates to an assembly for removing orreducing the level of contaminants in a solution comprising: a pluralityof light sources spaced in a radial array between a first photoelectrodeand a second photoelectrode; at least one counterelectrode providedbetween the first photoelectrode and the second photoelectrode; whereinthe first photoelectrode and second photoelectrode each comprise aprimarily titanium foil support with a layer of titanium dioxideprovided on at least one surface the photoelectrode; and wherein thefirst photoelectrode, second photoelectrode and at least onecounterelectrode are each coupled to a respective terminal adapted to beelectrically coupled to a power supply.

The present disclosure further relates to an apparatus for removing orreducing the level of contaminants in a solution comprising: a housingmember having first opposing end and a second opposing end and at leastpartially defining a cavity having a cavity wall and a cavitylongitudinal axis; a first light source provided within the cavity; afirst photoelectrode provided between the first light source and thecavity wall; a second photoelectrode provided between the firstphotoelectrode and the cavity wall; a plurality of second light sourcesprovided between the first photoelectrode and the second photoelectrode;a counterelectrode provided between the first photoelectrode and thecavity wall; wherein the first photoelectrode and second photoelectrodeeach comprises a primarily titanium foil support with a layer oftitanium dioxide provided on at least one surface the photoelectrode;and wherein the first photoelectrode, second photoelectrode andcounterelectrode are each coupled to a respective terminal adapted to beelectrically coupled to a power supply.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be better understood, and features, aspects andadvantages other than those set forth above will become apparent whenconsideration is given to the following detailed description thereof.Such detailed description makes reference to the following drawings,wherein:

FIG. 1 is an isometric view of a PECO system, according to variousembodiments.

FIG. 2 is an isometric view of a PECO system, according to variousembodiments.

FIG. 3 is an isometric cross-sectional view of the PECO system shown inFIG. 2, according to various embodiments.

FIG. 4 is an isometric cross-sectional view of a PECO apparatus,according to various embodiments.

FIG. 5 is an isometric view of a reactor assembly, according to variousembodiments.

FIG. 6 is an isometric cross-sectional view of a PECO apparatus,according to various embodiments.

FIG. 7 is a cross-sectional view of a PECO apparatus, according tovarious embodiments.

FIG. 8 is a cross-sectional view of a PECO apparatus, according tovarious embodiments.

FIG. 9 is a cross-sectional view of a PECO apparatus, according tovarious embodiments.

FIG. 10 is a cross-sectional view of a PECO apparatus, according tovarious embodiments.

FIG. 11 is a cross-sectional view of a PECO apparatus, according tovarious embodiments.

FIG. 12 is a cross-sectional view of a PECO apparatus, according tovarious embodiments.

FIG. 13 is a cross-sectional view of a PECO apparatus, according tovarious embodiments.

FIG. 14 is a cross-sectional view of a PECO apparatus, according tovarious embodiments.

FIG. 15 is an isometric view of a spacer, according to variousembodiments.

FIG. 16 is a top view of a spacer, according to various embodiments.

FIG. 17 is a side view of a spacer, according to various embodiments.

FIG. 18 is an isometric view of a light source assembly, according tovarious embodiments.

FIG. 19 is a partial isometric view of the light source assembly shownin FIG. 18, according to various embodiments.

FIG. 20 is a partial isometric view of a PECO system, according tovarious embodiments.

FIG. 21 is a partial side view of a PECO system, according to variousembodiments.

FIG. 22 is a partial isometric view of a PECO apparatus, according tovarious embodiments.

FIG. 23 is an isometric view of a bulkhead member, spigot member, bandand clamp, according to various embodiments.

FIG. 24 is an isometric view of a bulkhead member, spigot member, bandand clamp, according to various embodiments

FIG. 25 is a top view of a bulkhead member and band, according tovarious embodiments.

FIG. 26 is a cross-sectional view of the bulkhead member and bandillustrated in FIG. 25, according to various embodiments.

FIG. 27 is an isometric view of a spigot member and seal, according tovarious embodiments.

FIG. 28 is an isometric view of a bulkhead member, according to variousembodiments.

While the disclosure is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and are herein described below in detail. Forexample, any numbers, measurements, and/or dimensions illustrated in theFigures are for purposes of example only. Any number, measurement ordimension suitable for the purposes provided herein may be acceptable.It should be understood that the description of specific embodiments isnot intended to limit the disclosure from covering all modifications,equivalents and alternatives falling within the spirit and scope of thedisclosure.

DETAILED DESCRIPTION

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which the disclosure belongs. Although any methods andmaterials similar to or equivalent to those described herein may be usedin the practice or testing of the present disclosure, example methodsand materials are described below.

Various embodiments of system, apparatus, and device (e.g., aphotoelectrocatalytic oxidation (PECO) system, apparatus, and device)are described. Referring to FIGS. 1 and 2, a photoelectrocatalyticoxidation (PECO) system 100 is shown. In various embodiments, PECOsystem 100 includes at least one input 110 and at least one output 120and at least one PECO apparatus 130. In various embodiments, the inputand/or output are threaded to facilitate engagement or connection (e.g.,fluid connection) of input and/or output with a hose or otherfluid-conveying member. In various embodiments, input 110 is fluidlyconnected to an input manifold 140 that branches into multiple inputmanifold openings fluidly connected to one or more PECO apparatus 130 ofPECO system 100. In various embodiments, output 120 is fluidly connectedto an output manifold 150 that branches into one or more output manifoldopenings fluidly connected to one or more PECO apparatus 130 of PECOsystem 100. While input 110 is shown in the Figures as beginning orextending lower in elevation than or below each PECO apparatus 130 ofsystem 100, the input may be elevated above one or more of the PECOapparatus of the PECO system. While output 120 is illustrated in theFigures as beginning or extending higher in elevation than or above eachPECO apparatus 130 of system 100, the output may be lower in elevationthan or below one or more of the PECO apparatus of the PECO system. Invarious embodiments, the output may also be coupled or fluidly connectedto an output fitting (such as a u-shaped fitting) (not shown) to make iteasier to couple (e.g., fluidly couple) a hose or further fittings tothe output. The output fitting may also include a vent.

In various embodiments, PECO apparatus 130 is elevated at one end (e.g.,at the end closest to the output) relative to the other. This mayencourage collection of gases at the one end and may also help solutionto completely, substantially, or optimally fill PECO apparatus 130during use. Input 110 may be provided relatively lower in elevation orbelow PECO apparatus 130 and output 120 may be provided relativelyhigher in elevation or above PECO apparatus 130 to also help completely,substantially, or optimally fill PECO apparatus 130 during use.

Input manifold 140 and output manifold 150 each helps to allow multiplePECO apparatus 130 of PECO system 100 to be configured and/or utilizedin parallel. It should be appreciated, however, that the PECO apparatusof the PECO system may also be utilized in series, or alone, in variousapplications and embodiments. For example, in various embodiments, oneor more of the input manifold branches and one or more of the outputmanifold branches may be coupled to a valve 160 to help regulate and/orcontrol flow through PECO apparatus 130 or PECO system 100 generally.

Multiple PECO systems 100 may be operatively and/or fluidly connectedtogether (e.g., in series). For example, the output of a first PECOsystem may be fluidly connected to the input of a second PECO system tooperatively and fluidly connect the systems in series. In various otherembodiments, multiple PECO systems may be operatively or fluidlyconnected in parallel.

As shown in FIGS. 1 and 2, in various embodiments, each PECO system 100includes multiple PECO apparatus 130. While four PECO apparatus 130 areshown in FIGS. 1 and 2, it should be appreciated that any number of thePECO apparatus may be utilized in connection with the PECO systemdisclosed herein. Also, while multiple PECO apparatus 130 are shown in astacked (e.g., vertically-stacked) arrangement, any variety ofarrangements and configurations may be utilized within the scope of thisdisclosure. For example, multiple PECO apparatus may be provided in arow (e.g., side-to-side), in two rows of two, etc.

In various embodiments, PECO system 100 and/or PECO apparatus 130includes and/or is a substantially self-contained system and/orapparatus (apart from the input or in-flow and output or out-flowapertures, gas vents, etc.). Each PECO apparatus 130 in variousembodiments includes a housing, chamber, or container 170 which isadapted to at least partially receive components (e.g., one or moreoperative components) of PECO apparatus 130 and/or at least temporarilyreceive, contain and/or circulate fluid or aqueous solution.

In various embodiments, housing 170 includes at least one generallyannular, tubular (e.g., a square or rectangular tube), cylindrical orconical housing member 180 extending between a first opposing end 190and a second opposing end 200. Housing member 180 of each PECO apparatus130 may be formed of any suitable materials, or combination ofmaterials, and be of any size or shape suitable for its intendedpurposes. In one or more examples of embodiments, housing member 180 isa molded, high-durability plastic or polyethylene (e.g., PVC) and/or maybe formed to be resistant to one or more contaminants. Housing member180 may also take alternative shapes, sizes, and configurations. One ormore components of housing 170 and/or housing member may also beconstructed of metal which may be lined (e.g., with an inert polymercompound such as Teflon or PPS material).

In various embodiments, housing 170 includes a first fitting 190provided about first opposing end 210 and a second fitting 200 providedabout second opposing end 220 of housing member 180. Fittings 190/200may be formed of any suitable materials, or combination of materials,and be of any size or shape suitable for their intended purposes. In oneor more examples of embodiments, fittings 190/200 are made of ahigh-durability plastic or polyethylene (e.g., PVC) and/or may be formedto be resistant to one or more contaminants. In one or more otherexamples of embodiments, the fittings are made of metal. Alternativematerials and shapes suitable for the purposes of the system and/orapparatus are also acceptable.

In various embodiments, fittings 190/200 are T-fittings defining one ormore in-flow apertures and/or out-flow apertures. In variousembodiments, the in-flow and out-flow apertures defined by fittings190/200 are fluidly connected to input 110 and/or input manifold 130,and/or output 120 and/or output manifold 140. The locations of thein-flow and out-flow apertures may vary depending upon the desiredresults (e.g., the flow of solution through the apparatus, the timingand/or length of time thereof, other system configurations, etc.). Forexample, the in-flow and out-flow apertures may be provided through thehousing member or ends of the PECO apparatus. In addition, theorientation of the in-flow and out-flow apertures (e.g., relative toeach other) may be different than or modified from that shown in theFigures.

In various embodiments, one or both fittings 190/200 define a fittingcavity or other feature shaped to fit snugly or tightly to or otherwisereceive or be received by one or both opposing ends 210/220. However,one or both of the fittings may be coupled with or to the opposing endsand/or the housing member in other ways (e.g., through a threadedconnection or by butting the respective fitting to or near the first andsecond opposing ends). In various embodiments, a seal (e.g., an O-ring)is provided between one or both of fittings 190/200 and opposing ends210/220.

Referring now to FIGS. 3-4, in various embodiments, one or more housingwalls or sidewalls 230 of housing member 180 help define at least onehousing cavity 240. In various embodiments, housing cavity 240 issubstantially or entirely annular, tubular, cylindrical, or conical inshape (e.g., cross-sectional shape). In various embodiments, apart fromthe in-flow apertures and out-flow apertures, any drainage apertures andgas vents, housing cavity 240 is sealed or substantially sealed (e.g.,from an outside environment and/or an environment exterior to housing170) to prevent various elements (e.g., air or oxygen) from enteringhousing cavity 240 and/or various elements (e.g., a solution) fromexiting or escaping housing cavity 240, except through the in-flowand/or out-flow or drainage apertures, or vents (e.g., one-way vents).For example, in various embodiments, the PECO system or PECO apparatusincludes an area for collecting or allowing gases to gather oraccumulate and/or a valve or other component for bleeding off orremoving one or more gases (e.g., hydrogen (H2) or otherwise allowingthem to escape from inside the PECO apparatus or system. In variousembodiments, gases collect (e.g., at a high point of the system or anapparatus) and a float style valve allows the release of such gaseswhile preventing fluid in the apparatus or system from escaping. Theexit port on such a valve may be directed as necessary or desired (e.g.,to the outside, for collection, etc.). In various embodiments, the PECOapparatus may include a drainage apparatus or feature (e.g., to helpdrain solution before servicing).

In various embodiments, housing cavity 240 is adapted to receive variouscomponents of PECO apparatus 130. In various embodiments, at least onereactor assembly 250 is at least partially provided in or received byhousing cavity 240. In various embodiments, multiple (e.g., two) reactorassemblies 250 are provided in housing cavity 240. For example, and asshown in FIGS. 3-4, a reactor assembly 250 may be provided in first andsecond opposing ends 210/220. In various embodiments, each reactorassembly 250 extends from about opposing ends 210/220 into housingcavity 240 of PECO apparatus 130. While each reactor assembly 250 isshown in the Figures as extending nearly halfway into a length ofhousing cavity 240, it should be appreciated that the reactor assemblymay extend into any length (including substantially the entire length)of the housing cavity.

Referring now to FIGS. 5-7, in various embodiments, reactor assembly 250includes at least one counterelectrode (e.g., cathode) 260, at least afirst photoelectrode (e.g., anode) 270, and at least a first lightsource (e.g., UV-light source) or first light source assembly 280. Invarious embodiments, reactor assembly 250 includes a secondphotoelectrode 290, and one or more second light sources or second lightsource assemblies 300. In various embodiments, first photoelectrode 270is provided around first light source assembly 280.

In various embodiments, reactor assembly 250 includes first light sourceassembly 280 (e.g., a centralized UV light source) with one or moresecond light source assemblies 300 (e.g., six additional UV lightsources) provided (e.g., in a spaced relationship) around first lightsource assembly 280. In various embodiments, first light source assembly280 is provided about a longitudinal axis 305 of reactor assembly 250.In various embodiments, one or more second light source assemblies 300are spaced around longitudinal axis 305. In various embodiments, one ormore second light source assemblies 300 are generally spacedsymmetrically around longitudinal axis 305. In various embodiments, oneor more counterelectrodes 260 or cathodes are provided (e.g., in aspaced relationship) around first light source assembly 280 (e.g., inone or more of the spaces between the second light source assemblies300). In various embodiments, one or more counterelectrodes or cathodes260 (e.g., counterelectrode or cathode strips) are provided offset fromtheir mounting hole centerlines. Among other things, this may allowadditional counterelectrodes (e.g., an additional counterelectrode foreach offset mounting hole) to be added to the reactor assembly asnecessary or desired to help balance or otherwise better optimizereactions (e.g., with first and/or second photoelectrodes 270/290.

In various embodiments, reactor assembly 250 includes secondphotoelectrode 290 provided between first photoelectrode 270 and housingwall 230. In various embodiments, reactor assembly 250 includes a secondlight source assembly 300 provided between first photoelectrode 270 andsecond photoelectrode 290. In various embodiments, reactor assembly 250includes multiple second light source assemblies 300 (e.g., spacedsecond light source assemblies) provided between first light sourceassembly 280 and second photoelectrode 290 and/or housing wall 230. Invarious embodiments, one or more second light source assemblies 300 arespaced in a radial array between first photoelectrode 270 and secondphotoelectrode 290.

One or more of the counterelectrodes may be provided in a variety ofpositions in the reactor assembly, and/or the PECO apparatus. Forexample, in various embodiments, at least one counterelectrode 260 isprovided between multiple first and/or second light source assemblies280/300. As another example, at least one counterelectrode 260 may beprovided in a space between housing wall 230 and the one or more lightsource assemblies. In one or more examples of embodiments, one or morecounterelectrodes 260 are provided in a spaced relationship radiallyaround first photoelectrode 270. In various embodiments, one or morecounterelectrodes 260 are provided between first photoelectrode 270 andsecond photoelectrode 290. In various embodiments, the one or morecounterelectrodes 260 are arranged between the first photoelectrode 270and second photoelectrode 290 and second light source assemblies 300(e.g., on a line or ring concentric to the longitudinal axis of firstlight source assembly and/or housing member 180).

It should be appreciated that, while seven light source assemblies280/300 are shown in the FIGS. 5-7, any number of light sourceassemblies may be utilized and/or included in the reactor assembly. Itshould also be appreciated that, while six counterelectrodes 260 areshown in the FIGS. 5-7, any number of the counterelectrodes may beutilized and/or included within or as part of the reactor assembly.

In various embodiments, reactor apparatus 250 includes first lightsource assembly 280 centrally located within a space from housing wallor walls 230 and one or more second light source assemblies 300 betweenfirst light source assembly 280 and housing wall or walls 230. Forexample, reactor assembly 250 may include first light source assembly280 at or near the longitudinal axis of housing cavity 240 at leastpartially surrounded, encircled, and/or ringed by multiple (e.g., six)second light source assemblies 300, each of which is provided withinhousing cavity 240.

It should be noted, however, that the light source assemblies may beprovided with the housing cavity in any variety of ways and locations,and it is not necessary that the light source assemblies be providedconcentrically within and/or centrally spaced from the wall or wallsforming or defining the housing cavity. Rather, the light sourceassemblies may be provided in any variety of positions and/orconfigurations without departing from the spirit and scope of thisdisclosure. In various embodiments, the reactor assembly also includes ameans for cleaning or unfouling the light sleeve or tube of the one ormore light source assemblies.

In various embodiments, one or more first and second photoelectrodes270/290 are provided within housing cavity 240. In various embodiments,first photoelectrode 270 is provided at least substantially around firstlight source assembly located on or about the longitudinal or centralaxis of the housing cavity 240. In various embodiments, secondphotoelectrode 290 may be wrapped, wound, or otherwise provided at leastsubstantially around first photoelectrode 270 and one or more lightsource assemblies 280/300, and/or housing wall 230. In variousembodiments, first photoelectrode 270 is provided between a centrallylocated first light source assembly and one or more second light sourceassemblies 300. In various embodiments, second photoelectrode 290 isprovided between all light source assemblies of the reactor assembly andthe housing wall 230.

In various embodiments, first photoelectrode 270 (e.g., anode) may bewrapped, wound, or otherwise provided around and/or between first lightsource assembly 280 concentric within and/or spaced apart from thehousing wall 230 and one or more second photoelectrodes 290. In variousembodiments, second photoelectrode 290 may be wrapped, wound, orotherwise provided around and/or between first photoelectrode 270 andhousing wall 230. In examples of embodiments, one or more second lightsource assemblies 300 are provided between first photoelectrode 270 andsecond photoelectrode 290.

In one or more examples of embodiments, first photoelectrode 270 andsecond photoelectrode 290 (e.g., a foil photoelectrode) are wrapped,wound, or otherwise provided within housing cavity 240 such that amajority or substantial portion of UV light or radiation (e.g., from thefirst and second light source assemblies) with housing cavity 240 isdirected at or otherwise exposed to first and second photoelectrodes270/290.

It should be appreciated that any number of photoelectrodes and lightsource assembly configurations may be utilized within a scope of thisdisclosure. In various embodiments, the photoelectrodes are provided(e.g., around the light source assemblies) to optimize the distance,separation or spacing between the photoelectrodes and the light sourceassemblies. In various embodiments, one or more photoelectrodes may bewrapped, wound, or otherwise provided around the surface of a light tubeor sleeve of each light source assembly, multiple light tubes orsleeves, or one light tube or sleeve. The photoelectrodes may beprovided closely or tightly around or against each light sourceassembly. In various embodiments, a photoelectrode may be coupled (e.g.,removably coupled) to a light source assembly.

In various embodiments, and as shown in FIGS. 5-7, reactor assembly 250also includes one or more spacer members 310. One or more spacer members310 may be utilized, for example, to keep reactor assembly componentssuch as the first and/or second photoelectrodes 270/290,counterelectrodes 260, and first and/or second light source assemblies280/300 in a desired spatial relationship relative to each other, othercomponents, and/or housing wall 230. In various embodiments, portions ofspacer member 310 are adapted to receive first and second light sourceassemblies 280/300. In various embodiments, spacer member 310 is adaptedto help maintain separation or spacing between at least a portion offirst and second photoelectrodes 270/290 and one or morecounterelectrodes 260 (e.g., to prevent shorting or arcing near an edgeor end of reactor assembly 250.

Referring now to FIGS. 8-9, in various embodiments, reactor assembly 250includes one or more second light source assemblies 300 (e.g., sixsecond light source assemblies) arranged around first light sourceassembly 280 on a line or ring 315 concentric to a longitudinal axis ofreactor apparatus 250 and/or first light source assembly 280. In variousembodiments, reactor assembly 250 or PECO apparatus 130 may include moreor less than six of the second light source assemblies and/or more orless than six of the counterelectrodes. In various embodiments, reactorassembly 250 of PECO apparatus 130 includes less than six (e.g., five)second light source assemblies 300 provided between first light sourceassembly 280 (and/or first photoelectrode 270), and secondphotoelectrode 290 (and/or housing wall 230). In various embodiments,reactor assembly 250 of PECO apparatus 130 includes less than six (e.g.,five) counterelectrodes spatially arranged or otherwise provided betweenfive second light source assemblies 300 and arranged or provided betweenfirst light source assembly 280 (and/or first photoelectrode 270), andsecond photoelectrode (and/or wall 230). In various embodiments, PECOapparatus 130 includes one or more counterelectrodes 260 spatiallyarranged between multiple second light source assemblies 300 andprovided between first light source assembly 280 (and/or firstphotoelectrode 270), and second photoelectrode (and/or wall 230).Referring now to FIG. 10, in various embodiments, PECO apparatus 130includes multiple second light source assemblies 300 provided betweenfirst light source assembly 280 (and/or first photoelectrode 270), andat least one counterelectrode 260 (and/or wall 230).

Referring now to FIGS. 11-14, reactor assembly 250 or PECO apparatus 130may include one or more second photoelectrodes 290 provided around oneor more second light source assemblies 300 and one or morecounterelectrodes 260 provided around second photoelectrodes 290. Forexample, PECO apparatus 130 in various embodiments includes multiplesecond light source assemblies 300 provided around first light sourceassembly 280 (and/or the longitudinal axis of housing member 180 of PECOapparatus 130), one or more second photoelectrodes 290 provided aroundone or more second light source assemblies 300 and at least onecounterelectrode 260 provided around second photoelectrodes 290 and/orbetween second photoelectrodes 290 and wall 230. In various embodiments,the reactor assembly may not include the first light source assembly.

While the figures show a variety of light source assembly configurationsincluding a seven light source assembly configuration, a six lightsource assembly configuration, and a sixteen light tube or sleeveconfiguration, it should be appreciated that any number of light tubesor sleeves in any variety of configurations may be utilized or otherwiseprovided.

Referring again to FIG. 5, in various embodiments, reactor assembly 250includes a bulkhead member 320. In various embodiments, bulkhead member320 defines a first light source aperture 330 and one or more secondlight source aperture 340 between the first light source aperture and aperimeter 350 of bulkhead member 320. For example, as shown in FIG. 5,bulkhead member 320 may define a central first light source aperture 330and multiple similarly-sized second light source apertures 340 whosecenters are arranged around first light source aperture 330 on a lineconcentric to a center of central light source aperture 330 and/or acenter of bulkhead member 320. First and second light source aperture330/340 is, in various embodiments, adapted to retain and/or releasablyretain a first and/or second light source assembly 280/300. In variousembodiments, first and second light source apertures 330/340 are adaptedto receive a light source assembly such as an assembly shown in FIGS.18-19. In various embodiments, such assemblies include one or more lighttubes or sleeves. In various embodiments, the bulkhead member may alsodefine a recess into which a printed circuit board may be mounted forcontrolling the operation of the device or apparatus.

In various embodiments, one or more counterelectrode and/orphotoelectrode apertures are defined by bulkhead member 320. In variousembodiments, the one or more counterelectrode and photoelectrodeapertures defined by bulkhead member 320 are provided between and/ornear two or more light source apertures 330/340 to allow a bias orpotential to be applied to photoelectrodes 270/290 and counterelectrodes260 of reactor assembly 250. It should be appreciated that, while sevenlight source apertures 330/340 are shown, any number of the light sourceapertures may be defined by the bulkhead member. It should also beappreciated that, while six counterelectrode apertures and twophotoelectrode apertures are defined by bulkhead member 320 are shown inthe Figures, any number of the photoelectrode apertures and thecounterelectrode apertures may be defined by the bulkhead member.

In various embodiments, terminals, terminal configurations and/or leadsare electrically coupled to the photoelectrodes. The leads are adaptedto receive an applied voltage bias, potential and/or current provided bya power source connected or otherwise coupled (e.g., electricallyconnected coupled) to the leads. The leads are formed of a conductivematerial, such as a conductive metal. One or more of the leads maydefine or be provided with an aperture for ease of connection orcoupling of the lead to a wire, electrical cable or the like.

While not shown, the photoelectrode(s) and counterelectrode(s) may beseparated by a separator. Each separator may be used or otherwiseprovided to prevent shorting. In one or more examples of embodiments,each photoelectrode (e.g., anode) and counterelectrode (e.g., cathode)are separated by plastic or plastic mesh separator, although alternativeseparators (e.g., other dielectric material(s) or other separatorsaccomplishing or tending to accomplish the same or similar purposes) maybe acceptable for use with the device and system described herein.

In various embodiments, first and second photoelectrodes 270/290 includea conductive support member and a film member. In one or more examplesof embodiments, the conductive support member is constructed from metal(e.g., titanium or Ti). In various embodiments, the film member isnanoporous and includes a thin layer (e.g., 200-500 nm) of titaniumdioxide (TiO₂) (e.g., a TiO₂ coating) that is provided and/or adapted tofunction as a photocatalyst. In various examples of embodiments, thefilm member has an average thickness in the range of 1-2000 nanometers.In one or more examples of embodiments, the film member has an averagethickness in the range of 5 to 500 nanometers.

In various embodiments, the film member is provided on (e.g., coated onor adhered to) the conductive support member. In various embodiments,the film member has a median pore diameter in the range of 0.1-500nanometers and is constructed from TiO₂ nanoparticles. In one or moreexamples of embodiments, the median pore diameter of the film member isin the range of 0.3-25 nanometers. In other examples of embodiments, themedian pore diameter of the film member is in the range of 0.3-10nanometers.

In various examples of embodiments, the film member is constructed froma stable, dispersed suspension comprising TiO₂ nanoparticles having amedian primary particle diameter in the range of 1-50 nanometers. Thenanoporous film may also be deposited by other methods, such as plasma,chemical vapor deposition or electrochemical oxidation. In one or moreexamples of embodiments, the TiO₂ nanoparticles have a median primaryparticle diameter in the range of 0.3-5 nanometers.

In various embodiments, the film member is constructed from a stable,dispersed suspension including a doping agent. Examples of suitabledoping agents include, but are not limited to, Pt, Ni, Au, V, Sc, Y, Nb,Ta, Fe, Mn, W, Co, Ru, Rh, P, N and/or carbon (including carbonnanotubes, fullerenes, graphene, etc.).

In various examples of embodiments, the nanoporous film member isconstructed by applying a stable, dispersed suspension having TiO₂nanoparticles suspended therein. In various embodiments, the TiO₂nanoparticles are sintered at a temperature in the range of 300 deg C to1000 deg C for 0.5 to 24 hours. Example photoelectrodes may be preparedby coating Ti metal foil. Titanium foil is stable and may also be usedto make the first and second photoelectrodes. One example of suitable Timetal foil includes 15 cm×15 cm×0.050 mm thickness and 99.6+% (byweight) pure Ti metal foil commercially available from Goodfellow Corp.(Oakdale, Pa.) with a titania-based metal oxide. In various embodiments,the Ti metal foil is cleaned with a detergent solution, rinsed withdeionized water, rinsed with acetone, and/or heat-treated at 350 deg Cfor 4 hours providing an annealed Ti foil Annealing may also beconducted at higher temperatures such as 500 deg C.

Following cleaning and/or pretreatment, in various embodiments, themetal foil may be dip-coated. For example, the metal foil may bedip-coated three to five times with an aqueous suspension of titania ata withdrawal rate of ˜3.0 mm/sec. After each application of coating, invarious embodiments, the coated foil is air dried for about 10-15 minand then heated in an oven at 70 deg C to 100 deg C for about 45 min.After applying a final coating, in various embodiments, the coated foilis sintered at 300-600 deg C (e.g., 300 deg C, 400 deg C or 500 deg C)for 4 hours at a 3 deg C/min ramp rate. The Ti foil may be dipped intosuspensions of titania synthesized using methods disclosed in U.S.patent application Ser. Nos. 11/932,741 and 11/932,519, each of which isincorporated herein by reference in its entirety. In variousembodiments, the optimized withdrawal speed is around 21.5 cm min⁻¹.

In addition, in one or more examples of embodiments, the stable,dispersed suspension is made by reacting titanium isopropoxide andnitric acid in the presence of ultrapure water or water purified byreverse osmosis, ion exchange, and one or more carbon columns. Invarious embodiments, the conductive support member is annealed titaniumfoil. Other conductive supports may be employed, such as conductivecarbon or glass. In various other embodiments, the first and secondphotoelectrode may be constructed from an anatase polymorph of Ti or arutile polymorph of Ti. In one or more examples of embodiments, therutile polymorph of Ti is constructed by heating an anatase polymorph ofTi at a temperature in the range of 300 deg C to 1000 deg C for asufficient time. In one or more examples of embodiments, the anatasepolymorph of Ti is heated at 500 deg C to 600 deg C to produce therutile polymorph of Ti.

In various embodiments, after the titanium support is provided with alayer or film of TiO₂, the composite electrode is air-heated at a hightemperature, giving the nanoporous TiO₂ film a crystalline structure dueto thermal oxidation. It is believed that the instant titania, whenheated at 500 deg C, converts to a crystalline rutile polymorphstructure. It is further believed that the instant TiO₂ heated at 300deg C converts to a crystalline anatase polymorph structure. In somePECO applications, rutile TiO₂ has substantially higher catalyticactivity than the anatase TiO₂. Rutile TiO₂ may also have substantiallyhigher catalytic activity with respect to certain contaminant such asammonia.

The first and/or second photoelectrodes may be modified (e.g., toimprove performance). In various embodiments, the photoelectrodes (e.g.,Ti foil) are modified to increase the surface area of thephotoelectrodes exposed to light such as UV light. For example, thephotoelectrodes may be corrugated. As another example, thephotoelectrodes may be wavy. The photoelectrodes may include variousother features or microfeatures to help optimize the surface exposed toUV light and/or help cause turbulence in fluid or solution about thephotoelectrode.

In various embodiments, photoelectrode modifications include corrugatingor otherwise modifying the photoelectrodes, conductive support member orfoil to produce a wave-like pattern (e.g., regular wave-like pattern) onthe foil surface. In various embodiments, the height of a corrugation“wave” is from about 1-5 mm. For example, in various embodiments,corrugating the foil twice at right angles to each other produces across-hatched pattern on the foil surface.

In various embodiments, the photoelectrode modifications include holesor perforations made, defined by or provided in photoelectrodes,conductive support member, or foil. In various embodiments, the holes orperforations are made or provided at regular intervals (e.g., 0.5 to 3cm spacing between the holes).

Modifications of the photoelectrodes may also include variousmicrofeatures and/or microstructures. Accordingly to variousembodiments, the modifications of the photoelectrodes, conductivesupport members or foils may also include various microfeatures and/ormicrostructures that increase the relative surface area of thephotoelectrodes and/or increase or promote turbulence about thephotoelectrodes. For example, according to various embodiments, suchmicrofeatures and/or microstructures include those that are disclosed inU.S. Patent Publication Nos. 20100319183 and 20110089604, each of whichis incorporated herein by reference in its entirety, or suchmicrofeatures and/or microstructures that are provided commercially fromHoowaki, LLC (Pendleton, S.C.). In various embodiments, themicrofeatures may include microholes. In various embodiments,modifications of the photoelectrodes include the formation of nanotubes(e.g., TiO₂ nanotubes) on the photoelectrodes, conductive supportmembers and/or foils such as, for example, those that are disclosed inU.S. Patent Publication No. 20100269894, which is incorporated herein byreference in its entirety.

As a result of the holes, the positioning, the corrugation, and othermodifications, etc., the photoelectrodes may help create turbulence influid flowing in and/or through the PECO apparatus. Additionally, one ormore holes may allow oxidants generated or produced on or near a surfaceof the photoelectrodes to more rapidly and effectively make their wayinto or otherwise reach or react with the fluid (e.g., aqueous solution)and/or contaminants therein.

In one or more examples of embodiments, the photoelectrodes are in theform of a mesh (e.g., a woven mesh, such as a 40×40 twill weave mesh or60×60 Dutch weave mesh, or a non-woven mesh).

In various embodiments, counterelectrode (e.g., cathode) 260 is in theform of a rod such as a rod with an L-shaped cross-section. However, thecounterelectrode may be in the form of a wire, foil, plate, cylinder, orin another suitable shape or form. In various embodiments, thecounterelectrode may be corrugated and/or have other features to helpcause or promote turbulence in fluid or solution in the cavity.

In one or more examples of embodiments, the counterelectrode or cathodeis constructed from or includes Al, Pt, Ti, Ni, Au, stainless steel,carbon and/or another conductive metal.

Referring now to FIGS. 15-17, in one or more examples of embodiments,spacer member 310 is a molded, durable plastic, or polyethylene, and/ormay be formed to be resistant to one or more contaminants. Spacer member310 may be made from plastics. In various embodiments, spacer member 310is made (e.g., molded) from a thermoplastic such a chlorinated polyvinylchloride (CPVC). In various embodiments, spacer member 310 is made(e.g., molded) from Fortron polyphenylene sulfate (PPS). The spacermember or portions thereof may be made of titanium (e.g., titanium sheetmetal). The spacer member made of conductive material such as titanium,however, may also include non-conductive mounting points forphotoelectrodes and/or counterelectrodes in electrical contact therewithto prevent electrical shorting.

In various embodiments, spacer member 310 includes one or more dividers350 extending between a peripheral concentric portion 325 and an axialconcentric portion 335. Divider 350 is adapted to help direct, redirect,mix, stir or otherwise influence solution as it passes through thespacer. Such mixing or flow may be advantageous in many ways. Forexample, such mixing or flow may help to mix oxidants generated by thedevice into the solution. As another example, such mixing or flow mayincrease the residence time of the solution in the cavity of the devicefor even a solution of moderate velocity. It should also be noted thatany number of spacers 310 may be utilized anywhere within the cavity. Invarious embodiments, spacer 310 allows for flanges to be provided alongthe length of each counterelectrode or cathode on either or both edgesof the counterelectrode or cathode to help create a counterelectrodesurface that is substantially parallel or otherwise aligned with asurface of the first and/or second photoelectrode or anode. In variousembodiments, the spacer has an optimal or minimal cross-sectional areato optimize or minimize any restrictions on flow through the device orapparatus.

Referring now to FIGS. 18-19, first and second light source assemblies280/300 include a light source 360 (e.g., a UV light) and a light tubeor sleeve 370. The light tube or sleeve may be formed of any materialsuitable for the purposes provided. For example, the light tube orsleeve may be UV-transparent material, such as, but not limited to,plastic or glass, or combinations of materials including suchUV-transparent and/or UV-translucent material. In one or more examplesof embodiments, light tube or sleeve 340 is made of quartz.Alternatively, the light source assemblies may not include a light tubeor sleeve.

In various embodiments, light tube or sleeve 370 includes at least onewall or sidewall 380 that helps define a tube cavity 390 that at leastpartially houses and/or is at least partially adapted to receive one ormore light sources 360 (e.g., an ultraviolet (UV) light source, light,or lamp). For example, a UV-light bulb or bulbs may be provided orinserted into the tube cavity. In various embodiments, light source 360is provided and/or extends a distance into tube cavity 390, such thatthe light (e.g., UV) provided thereby may be exposed to one or more ofthe first and second photoelectrodes (and/or one or more photoelectrodesmay be exposed to UV), illuminating or radiating to some or all of asurface thereof according to the various embodiments described herein.In various embodiments, each light tube or sleeve 370 is coupled to anadapter or end cap 400.

In various embodiments, end cap or adapter 400 is provided around andcoupled (e.g., glued) to an end of light tube or sleeve 370. In variousembodiments, adapter or end cap 400 defines an aperture through whichsensors and wiring 410 (e.g., wiring for powering a UV light source) andother connections may be provided. In various embodiments, at least aportion of adapter 400 is threaded. Any threads along with various seals(e.g., O-rings) help prevent fluid from leaking while also allowing eachlight source assembly to be removable from the reactor assembly (e.g.,for repair, replacement, etc.).

In various embodiments, the end cap or adapter further includes a glandcap. In various embodiments, wires are potted or otherwise sealed to thegland cap or adapter. In various embodiments, the gland cap provides afluid seal in the event of a break or leak of the light tube or sleeve.In various embodiments, the gland cap is screwed into threads providedin an aperture defined by the end cap or adapter. In variousembodiments, an O-ring is provided between the end cap and the gland capto provide a seal to prevent fluid from leaking outside of the cavity.In various embodiments, an additional seal such as a epoxy bead may beprovided between the end cap and the light tube or sleeve.

The light source may be provided or inserted into a socket provided inthe adapter and may be secured in position. Each light source is furthercoupled or connected (e.g., electrically connected via wiring 410 or asocket), or adapted to be coupled or connected, to a source of power. Invarious embodiments, the light source or UV bulb is coupled or connected(e.g., electrically) via one or more cables or wires to one or moreballasts and/or power sources. In various embodiments, light source 360extends into at least a majority of each light tube or sleeve 370.However, in various embodiments, the light source may extend onlypartially or not at all into the light tube or sleeve.

In various embodiments, light source 360 is a high irradiance UV lightbulb. In one or more further examples of embodiments, light source 360is a germicidal UV bulb with a light emission in the range of 400nanometers or less, and more preferably ranging from 250 nanometers to400 nanometers.

In various embodiments, the ultraviolet light of light source 360 has awavelength in the range of from about 185 to 380 nm. In one or moreexamples of embodiments, light source 360 is a low pressure mercuryvapor lamp adapted to emit UV germicidal irradiation at 254 nmwavelength. In one or more alternative examples of embodiments, a UVbulb with a wavelength of 185 nm may be effectively used as the lightsource. Various UV light sources, such as those with germicidal UVCwavelengths (peak at 254 nm) and black-light UVA wavelengths (UVA rangeof 300-400 nm), may also be utilized. In one or more examples ofembodiments, an optimal light wavelength (e.g., for promoting oxidation)is 305 nm. However, various near-UV wavelengths are also effective. Bothtypes of lamps may emit radiation at wavelengths that activatephotoelectrocatalysis. The germicidal UV and black light lamps arewidely available and may be used in commercial applications of theinstant PECO device.

In one or more additional examples of embodiments, light source 360 isadapted to emit an irradiation intensity in the range of 1-500 mW/cm².The irradiation intensity may vary considerably depending on the type oflight source used. Higher intensities may improve the performance of thedevice (e.g., PECO device). However, the intensity may be so high thatthe system is UV-saturated or swamped and little or no further benefitis obtained. That optimum irradiation value or intensity may depend, atleast in part, upon the distance between the lamp and one or morephotoelectrodes.

The intensity (i.e., irradiance) of UV light at the photoelectrode maybe measured using a photometer available from International LightTechnologies Inc. (Peabody, Mass.), e.g., Model IL 1400A, equipped witha suitable probe. An example irradiation is greater than 3 mW/cm².

UV lamps typically have a “burn-in” period. UV lamps may also have alimited life (e.g., in the range of approximately 6,000 to 10,000hours). UV lamps also typically lose irradiance (e.g., 10 to 40% oftheir initial lamp irradiance) over the lifetime of the lamp. Thus, itmay be important to consider the effectiveness of new and old UV lampsin designing and maintaining oxidation values.

The light source may be disposed exterior to the light tube or sleeve,and the tube or sleeve may include a transparent or translucent memberadapted to permit ultraviolet light emitted from the light source toirradiate the photoelectrode. The device may also utilize sunlightinstead of, or in addition to, the light source.

Referring now to FIGS. 20-21, in various embodiments, the light sourceassemblies are provided (e.g., threaded) through the light sourceapertures of bulkhead member 320 such that the light tubes or sleevesare provided within (e.g., within the cavity) and spaced from thewall(s) of the housing. In various embodiments, each light tube orsleeve is adapted to disburse, distribute or otherwise transport orprovide light over some, most, or all of the length of the light tube orsleeve, and/or some, most, or all of a length of the cavity. In variousembodiments, at least one light tube or sleeve is substantially centralto and/or substantially concentric within and spaced from the wall(s)(e.g., cylindrical walls) of the housing. In other embodiments, such aswhere the walls or cavity of the housing are not cylindrical, at leastone light tube or sleeve is substantially centrally-located and spacedfrom one or more of the walls.

In various embodiments, fitting 190 includes a fitting flange 420 towhich bulkhead member 320 is coupled or releasably coupled. Fittingflange 420 may be integral to the fitting or part of a component coupledto fitting 190. In various embodiments, fitting flange 420 and bulkheadmember 320 each defines one or more flange apertures 430 into whichbolts or other fasteners (not shown) may be provided to help releasablycouple and create a seal between bulkhead member 320 and fitting flange420.

In various embodiments, multiple counterelectrodes may beelectrically-coupled together (e.g., with first bus bars 440 or otherconductive material (such as stainless steel)). In addition, multiplephotoelectrodes may be electrically-coupled together with one or moresecond bus bars 450 or other conductive material. It should beappreciated that the bus bars may also be provided internally to areactor apparatus (e.g., to help protect them from damage, to reducepotential leaking, etc.). If provided internally, the bus bars may bemade of titanium.

In various embodiments, and referring now to FIGS. 22-28, a secondembodiment of a fitting 500 and bulkhead member 510 is shown. In variousembodiments, bulkhead member 510 is coupled to a spigot member 520coupled to fitting 500. As shown in FIGS. 8-10, spigot member 520includes a spigot flange 530 and bulkhead member 510 includes a bulkheadflange 540, which flanges 530/540 may be releasably compressed togetherutilizing a clamp 550 (e.g., V-band clamp). While not commonly used withPVC flanges, the V-band clamp may be utilized as desired (e.g., wherefrequent access is required, or where space is limited) in connectionwith certain flange configurations disclosed herein such as those shownin the Figures. In various embodiments, a relatively wide or extra wide,deep V-band flange profile is utilized to allow for extra flange depthand shear section and provide added seal strength. As shown, in variousembodiments, clamp 550 is a V-band clamp style (e.g., over center handlestyle clamp) to provide quick or easy access. In various embodiments,clamp 550 also includes multiple segments (e.g., three segments) toallow for greater flexibility for installation and removal. In variousembodiments, clamp 550 is provided with a T-bolt quick release latch. Itshould be appreciated, however, that any number of clamp and latchstyles, segment configurations, and profiles may be utilized. The clampmay be provided with a lubricant such as a dry film lubricant to helpevenly distribute the clamp pressure around the flanges and reduce anyneed to provide a lubricant on the flanges themselves. In variousembodiments, clamp 550 also includes a secondary latch 555 to preventthe inadvertent or unintended release of clamp 550.

As shown in FIGS. 27-28, in various embodiments, spigot member 520includes a spigot flange 530 (e.g., Van Stone spigot flange), andbulkhead member 510 includes a bulkhead flange 540 (e.g., matingflange). It should also be appreciated, however, that any variety offlange styles may be utilized. In various embodiments, a seal 560 (e.g.,O-ring seal) is provided between spigot member 520 and bulkhead member510 (e.g., when assembled or compressed together). In variousembodiments, the spigot member or bulkhead member may also define afeature (e.g., a dovetail feature such as an undercut dovetail) to helpretain seal 560 (e.g., an O-ring) relative to spigot member 520 and/orbulkhead member 510.

In various embodiments, spigot member 520 and bulkhead member 510 alsoincludes a tongue and groove feature. For example, in variousembodiments, bulkhead member 510 may include a tongue or ring 570 that,when bulkhead member 510 is properly aligned with spigot member 520,will fit into a groove or channel 580 defined by spigot member 520 tohelp align (e.g., coaxially align) spigot member 520 and bulkhead member510 relative to each other. Such ring 570 or inner ring may also helpprotect a sealing face 590 of bulkhead member 510 during shipping andhandling. In various embodiments, the seal 560 is provided on spigotmember 520 or flange 530 to allow easy visual access for inspection andcleaning of seal 560 to help ensure particular contaminants which maycompromise the integrity of seal 560 are removed during servicing. Aseal (e.g., O-ring) may be provided on the bulkhead flange as analternate or additional configuration.

The configuration of the clamp, spigot member 520, and mating bulkheadmember 510 may also improve ease of removal of system components, suchas a reactor assembly coupled to or otherwise associated with orincluding bulkhead member 510. For example, spigot 520 and/or spigotflange 530 may be shaped and sized to allow the clamp to be rested on oraround spigot member 520 (e.g., next to spigot flange 530) duringremoval and installation of bulkhead member 510. In addition, in variousembodiments, a profile of bulkhead flange 540 provides an area orfeature 600 that may be utilized to better grip bulkhead member 510 whenremoving it from the apparatus or otherwise relative to spigot member520.

In various embodiments, one or more power supplies and/or ballasts areincluded or provided for powering each light source and/or for providingan electrical potential or bias to one or more of the counterelectrodes(e.g., cathodes) and photoelectrodes (e.g., anodes). In variousembodiments, one or more power supplies and/or ballasts are electricallycoupled to the light sources and/or the photoelectrodes and providedexternally to the container, housing or apparatus. At least one pump mayoptionally be provided internally or externally to the housing to helpfacilitate transfer or movement of fluid or solution through eachapparatus or a system of apparatus. The pump may also be used, forexample, for circulation or recirculation.

Referring again to FIG. 1, an electrical or control panel 450 accordingto one or more examples of embodiments is shown. In various embodiments,electrical or control panel 450 includes one or more of the following:power supplies, controls and/or lamps for one or more PECO apparatus anda master control and lamp. In various embodiments, the control panel mayalso include a event indicator lamp and reset control. In variousembodiments, the control panel may be utilized to implement and/oroperate one or more of the apparatus, devices, systems, and/or methodsdescribed herein.

In various embodiments, control panel 450 may also include one or moreuser interfaces 460. For example, in various embodiments, user interface460 is used to configure, set-up, monitor and/or maintain one or more ofthe apparatus or systems described herein. The user interface mayinclude a button or other control for implement a sampling of solution.For example, it may be desirable to sample solution before and after itis treated using an apparatus, device, system or method describedherein. For example, in various embodiments, the apparatus or systemincludes two valves, one provided about at or about an input line forthe apparatus or system, and the other provided about an output line forthe apparatus or system. Such valves may be opened to help collectsolution samples. These samples may tested on-site and/or off-site(e.g., sent to a laboratory for testing). The testing may involvechemical analysis and/or biologic analysis (e.g., to determine bacteriacounts and/or “xxx log kill” measurements).

Because such testing may be affected by polarity applied or provided toelectrodes at the time of sampling and because testing results may bemore accurate if sampling is conducted at a time when polarity isconsistent between samples, the user interface in various embodimentsmay include a button or control (e.g., “START SMPL PROCESS” button) forplacing the system or apparatus in a particular state of polarity (e.g.,a positive or normal polarity or bias) for a predetermined or desiredtime period (e.g., two minutes) to allow sampling to occur during thattime period.

In various embodiments, power supplies, ballasts, circuit boards and/orcontrols may be housed or otherwise provided in the electrical orcontrol panel. The PECO system may also include temperature sensorsprovided at various positions (e.g., in each group of devices). Invarious embodiments, the electrical panels may include fans and/or heatsinks if desired. In various embodiments, the electrical panels may beprovided in an environment away from hazardous or flammable reactions.

One or more power supplies may also be provided for supplying power toone or more UV lamps. One or more power supplies, or an alternativepower supply may also be provided for providing an applied voltagebetween the photoelectrode and counterelectrode. In one or more examplesof embodiments, increasing the applied voltage increases photocurrentand/or chlorine production. In various embodiments, the applied voltagebetween the photoelectrode and the counterelectrode is provided to helpensure that electrons freed by photochemical reaction move or are movedaway from the photoelectrode. The power supply may be an AC and/or DCpower supply and may include a plurality of outputs.

One or more power supplies, in one or more examples of embodiments, maybe connected to a power switch for activating or deactivating the supplyof power. In one or more further examples of embodiments, a powersupply, UV lamps, and or electrodes, may be connected to or incommunication with programmable logic controller or other control orcomputer for selectively distributing power to the UV lamps and/or tothe electrodes, including anodes and cathodes described herein.

In various embodiments, one or more power supplies are external to thesystem. However, one or more power supplies may be internal to thesystem (e.g., in an electrical panel or box coupled to the device(s)).

The power supply or an additional power supply may be connected to theterminals of the electrodes described hereinabove via, for example cableconnection to the terminals, for providing a current, potential, voltageor bias to the electrodes as described in the described methods.

A temperature probe(s) or sensor(s) may also be provided in one or moreexamples of embodiments. For example, the temperature probe(s) may bepositioned in the housing or the adapter of the UV light assembly. Thetemperature probe may monitor the temperature in the device or in thefluid within the respective device and communicate that temperaturereading. Further the temperature probe may be in communication with ashut-off switch or valve which is adapted to shut the system down uponreaching a predetermined temperature.

A fluid level sensor(s) may also be provided which may communicate afluid level reading. The fluid level sensor(s) may be positioned in thedevice. Further the fluid level sensor may be in communication with ashut-off switch or valve which is adapted to shut off the device orincrease the intake of fluid into the device upon reaching apredetermined fluid value.

In one or more examples of embodiments, the device includes a carbonfilter adapted to filter chlorine from the water. In variousembodiments, the device includes a computer adapted to send one or morecontrolled signals to the existing power supplies to pulse the voltageand current.

In operation of the foregoing example embodiment, generally, in variousembodiments, a method for reducing the level or amount of one or morecontaminants in solution or fluid described includes introducing thesolution into a housing or container or cell including: at least onelight source; at least one photoelectrode (e.g., anode), wherein the atleast one photoelectrode includes an anatase polymorph of titanium, arutile polymorph of titanium, or a nanoporous film of titanium dioxide;and at least one counterelectrode (e.g., cathode). In variousembodiments, flow of fluid or solution is facilitated past or along oneor more photoelectrodes and/or counterelectrodes of a PECO apparatus. Invarious embodiments, one or more photoelectrodes are irradiated with UVlight, and a first potential or bias is applied to one or morephotoelectrodes and one or more counterelectrodes for a first period oftime. In various embodiments, a second potential or bias is applied tothe one or more photoelectrodes and counterelectrodes for a secondperiod of time. As a result, in various embodiments, a contaminant levelor amount in the solution introduced into the housing is reduced.

Contaminated fluid, such as contaminated water, may be pumped orotherwise provided or directed into an apparatus, or system. The watermay be circulated and/or recirculated within the device. Multiple units,or reactors, may be connected and operated in series, which may resultin increased space and time for contaminated fluid in the reactor(s) ordevice(s). Upon completion of processing, in various embodiments, thewater exits the device ready for use, or circulated or recirculatedthrough the device, one or more other devices, or system of devices, forfurther treatment or purification.

In various embodiments, in operation, the TiO₂ photocatalyst isilluminated with light having sufficient near UV energy to generatereactive electrons and holes promoting oxidation of compounds on theanode surface.

Any temperature of aqueous solution or liquid water is suitable for usewith the exemplary embodiments of the device such as the instant PECOdevices. In various embodiments, the solution or water is sufficientlylow in turbidity to permit sufficient UV light to illuminate thephotoelectrode.

In various embodiments, photocatalytic efficiency is improved byapplying a potential (i.e., bias) across the photoelectrode andcounterelectrode. Applying a potential may decrease the recombinationrate of photogenerated electrons and holes. In various embodiments, aneffective voltage range applied may be in the range of −1 V to +15 V. Invarious embodiments, an electrical power source is adapted to apply anelectrical potential in the range of 4 V to 12 V across thephotoelectrode and counterelectrode. In various embodiments, theelectrical power source is adapted to generate an electrical potentialin the range of 1.2 V to 3.5 V across the photoelectrode andcounterelectrode (or, 0 to 2.3 V vs. the reference electrode).

For various applications, including, for example fracking fluid orhigh-salinity applications, it may be desirable to reverse (e.g.,periodically or intermittently) the potential, bias, polarity and/orcurrent applied to or between the photoelectrode and thecounterelectrode (e.g., to clean the photoelectrode and/orcounterelectrode, or to otherwise improve the performance of thephotoelectrode, counterelectrode, or device). In various embodiments, byreversing the potential, bias, polarity and/or current, thephotoelectrode is changed (e.g., from an anode) into a cathode and thecounterelectrode is changed (e.g., from a cathode) into an anode. Invarious embodiments, circuit boards utilized by the device or system ofdevices may be utilized to reverse the bias as described.

For example, in various embodiments, initially positive voltage iselectrically connected to a positive charge electrode and negativevoltage is electrically connected to a negative charge electrode. Aftera first period of time, the positive voltage is electrically connectedto the negative charge electrode and the negative voltage iselectrically connected to the positive charge electrode. After a secondperiod of time, the positive voltage is electrically connected back tothe positive charge electrode and the negative voltage is electricallyconnected back to the negative charge electrode. This reversal processmay be repeated as necessary or desired.

The length of the first period of time and the second period of time maybe the same. In various embodiments, however, the length of the firstperiod of time and the second period of time are different. In variousembodiments, the first period of time is longer than the second periodof time.

The length of the first and second periods of time depends on a varietyof factors including salinity, application, voltage, etc. For example,fracking fluid or high salinity fluid applications may requirerelatively more frequent reversal of potential, bias, polarity and/orcurrent compared to fresh water applications. In various embodiments,the lengths of the first period of time relative to the second period oftime may be in a ratio of from 3:1 to 50:1, and in one or more furtherembodiments from 3:1 to 25:1, and in one or more further embodimentsfrom 3:1 to 7:1. For example, in various embodiments, the first periodof time and second period of time is about 5 minutes to about 1 minute.Fresh water applications may require relatively less frequent reversalof potential, bias, polarity and/or current, and the lengths of thefirst period of time relative to the second period of time may be in aratio of from 100:1 to 10:1. For example, in various embodiments, thefirst period of time and second period of time is about 60 minutes to arange of about 1 minute to about 5 minutes.

In various embodiments, the voltage applied between the photoelectrodeand counterelectrode may not change during the first period of time ofnormal potential and during the second period of time of reversepotential. For example, in various embodiments (e.g., where thephotoelectrode includes titanium and the apparatus and/or method areadapted for treatment of fracking or other high salinity solution) thevoltage applied during the first period of time may be less than 9V(e.g., about 7.5V) and the voltage applied during the second period oftime may be less than 9V (e.g., about 7.5V). In other variousembodiments (e.g., where the photoelectrode includes titanium and theapparatus and/or method are adapted for treatment of fresh water) thevoltage applied during the first period of time may be greater than 9V(e.g., about 12V) and the voltage applied during the second period oftime may be greater than 9V (e.g., about 12V).

Maintaining the voltage in the first period of time and the secondperiod of time may help to maintain and/or un-foul the photoelectrode tohelp make it more effective for removing contaminants throughphotoelectrocatalytic oxidation during the first period of time.However, maintaining the voltage under 9V in each period of time maycause a momentary disturbance in the removal of contaminants during thesecond period of time. For a variety of reasons, (e.g., to help minimizeany such disturbance and/or to help cause electroprecipitation and/orelectrocoagulation), in various embodiments, it may be advantageous toapply higher voltages (e.g., voltages greater than 9V) during the firstperiod of time and second period of time. In various embodiments,applying higher voltages helps to promote an electrochemical processsuch as electroprecipitation and/or electrocoagulation during the secondperiod of time, which process can help minimize any disturbance inremoval of contaminants during the second period of time as well asoffer advantages and benefits of such a process.

In various embodiments, the voltage is adjusted to control the rate ofdissolution of the electrode. In various examples of embodiments, thevoltage applied during the first period of time may be more than 9V(e.g., about 12V) and the voltage applied during the second period oftime may be more than 9V (e.g., about 12V). Higher voltages may helpoptimize the effectiveness of the device in certain ways. Highervoltages may also lead to electroprecipitation or electrocoagulation ofcontaminants within or from the fluid. However, such higher voltages mayalso lead to anodic dissolution such as pitting and other degradation ofthe photoelectrode and/or counterelectrode, which may necessitate morefrequent servicing of the PECO device (e.g., replacement of thephotoelectrode (e.g., the foil) and counterelectrode).

In various embodiments, it may be advantageous (e.g., to help limit anyanodic dissolution, or pitting or other degradation of thephotoelectrode) to apply relatively lower voltages during the firstperiod of time and relatively higher voltages during the second periodof time. In various embodiments, e.g., in a fracking fluid applicationusing a photoelectrode and a counterelectrode including titanium, thevoltage applied during the first period of time may be less than 9V(e.g., about 7.5V) and the voltage applied during the second period oftime may be more than 9V (e.g., about 12V for fracking fluid or highersalinity applications, to about 14V for fresh water applications). Invarious embodiments, during application of relatively lower voltageduring the first period of time, contaminants are degraded (or theremoval of contaminants is promoted) by photoelectrocatalytic oxidation,and during application of a relatively higher voltage during the secondperiod of time, contaminants are degraded (or the removal ofcontaminants is promoted) by an electrochemical process such aselectroprecipitation and/or electrocoagulation.

In various embodiments, during the second period of time, thecounterelectrode or sacrificial electrode of titanium is dissolved atleast in part by anodic dissolution. It is believed that a range ofcoagulant species of hydroxides are formed (e.g., by electrolyticoxidation of the sacrificial counterelectrode), which hydroxides helpdestabilize and coagulate the suspended particles or precipitate and/oradsorb dissolved contaminants.

In various embodiments, it is advantageous to apply relatively highervoltages during the first period of time and relatively lower voltagesduring the second period of time. In various embodiments, the voltageapplied during the first period of time is more than 9V (e.g., about12V) and the voltage applied during the second period of time is lessthan 9V (e.g., about 7.5V).

In various embodiments, the main reaction occurring at thecounterelectrodes or sacrificial electrodes during the second period oftime (e.g., during polarity reversal) is dissolution:

TI _((s)) →Ti ⁴⁺+4e ⁻

In addition, water is electrolyzed at the counterelectrode (orsacrificial electrode) and photoelectrode:

2H₂O+2e ⁻→H_(2(g))+2OH⁻ (cathodic reaction)

2H₂O→4H⁺+O_(2(g))+4e ⁻ (anodic reaction)

In various embodiments, electrochemical reduction of metal cations(Me^(n+)) occurs at the photoelectrode surface:

Me^(n+) +ne ⁻ →nMe^(o)

Higher oxidized metal compounds (e.g., Cr(VI)) may also be reduced(e.g., to Cr(III)) about the photoelectrode:

Cr₂O₇ ²⁻+6e ⁻+7H₂O→2Cr³⁺+14OH⁻

In various embodiments, hydroxide ions formed at the photoelectrodeincrease the pH of the solution which induces precipitation of metalions as corresponding hydroxides and co-precipitation with metal (e.g.,Ti) hydroxides:

Me^(n+) +nOH⁻→Me(OH)_(n(s))

In addition, anodic metal ions and hydroxide ions generated react in thesolution to form various hydroxides and built up polymers:

Ti⁴⁺+4OH⁻→Ti(OH)_(4(s))

nTi(OH)_(4(s)) ⁻→Ti_(n)(OH)_(4n(s))

However, depending on the pH of the solution other ionic species mayalso be present. The suspended titanium hydroxides can help removepollutants from the solution by sorption, co-precipitation orelectrostatic attraction, and coagulation.

For a particular electrical current flow in an electrolytic cell, themass of metal (e.g., Ti) theoretically dissolved from thecounterelectrode or sacrificial electrode is quantified by Faraday's law

$m = \frac{ItM}{zF}$

where m is the amount of counterelectrode or sacrificial electrodematerial dissolved (g), I the current (A), t the electrolysis time (s),M the specific molecular weight (g mol⁻¹), z the number of electronsinvolved in the reaction and F is the Faraday's constant (96485.34 Asmol⁻¹). The mass of evolved hydrogen and formed hydroxyl ions may alsobe calculated.

In various embodiments, it may be advantageous (e.g., to help limit anyanodic dissolution, or pitting or other degradation of thephotoelectrode) to apply certain voltages (e.g., relatively highervoltages) during the first period of time and different voltages (e.g.,relatively lower voltages) during the second period of time. In variousembodiments (e.g., in a fracking fluid application using acounterelectrode including aluminum), the voltage applied during thefirst period of time may be about 6V to 9V (e.g., about 7.5V) and thevoltage applied during the second period of time may be about 0.6V-12V.In various embodiments, during application of relatively higher voltageduring the first period of time, contaminants are degraded (or theremoval of contaminants is promoted) by photoelectrocatalytic oxidation,and during application of a relatively lower voltage during the secondperiod of time, contaminants are degraded (or the removal ofcontaminants is promoted) by and electrochemical process suchelectroprecipitation or electrocoagulation.

In various embodiments, during the second period of time, an aluminumcounterelectrode or sacrificial electrode is dissolved at least in partby anodic dissolution. It is believed that a range of coagulant speciesof hydroxides are formed (e.g., by electrolytic oxidation of thesacrificial counterelectrode), which hydroxides help destabilize andcoagulate the suspended particles or precipitate and/or adsorb dissolvedcontaminants.

In various embodiments, the main reaction occurring at thecounterelectrodes or sacrificial electrodes during the second period oftime (e.g., during polarity reversal) is dissolution:

Al_((s))→Al³⁺+3e ⁻

Additionally, water is electrolyzed at the counterelectrode (orsacrificial electrode) and photoelectrode:

2H₂O+2e ⁻→H_(2(g))+2OH⁻ (cathodic reaction)

2H₂O→4H⁺+O_(2(g))+4e ⁻ (anodic reaction)

In various embodiments, electrochemical reduction of metal cations(Me^(n+)) occurs at the photoelectrode surface:

Me^(n+) +ne ⁻ →nMe^(o)

Higher oxidized metal compounds (e.g., Cr(VI)) may also be reduced(e.g., to Cr(III)) about the photoelectrode:

Cr₂O₇ ²⁻+6e ⁻+7H₂O→2Cr³⁺+14OH⁻

In various embodiments, hydroxide ions formed at the photoelectrodeincrease the pH of the solution which induces precipitation of metalions as corresponding hydroxides and co-precipitation with metal (e.g.,Al) hydroxides:

Me^(n+) +nOH⁻→Me(OH)_(n(s))

In addition, anodic metal ions and hydroxide ions generated react in thesolution to form various hydroxides and built up polymers:

Al³⁺+3OH⁻→Al(OH)_(3(s))

nAl(OH)_(3(s)) ⁻→Al_(n)(OH)_(3n(s))

However, depending on the pH of the solution other ionic species, suchas dissolved Al(OH)²⁺, Al₂(OH)₂ ⁴⁺ and Al(OH)₄ ⁻ hydroxo complexes mayalso be present. The suspended aluminum hydroxides can help removepollutants from the solution by sorption, co-precipitation orelectrostatic attraction, and coagulation.For a particular electrical current flow in an electrolytic cell, themass of metal (e.g., Al) theoretically dissolved from thecounterelectrode or sacrificial electrode is quantified by Faraday's law

$m = \frac{ItM}{zF}$

where m is the amount of counterelectrode or sacrificial electrodematerial dissolved (g), I the current (A), t the electrolysis time (s),M the specific molecular weight (g mol⁻¹), z the number of electronsinvolved in the reaction and F is the Faraday's constant (96485.34 Asmol⁻¹). The mass of evolved hydrogen and formed hydroxyl ions may alsobe calculated.

The present invention, in one or more examples of embodiments, isdirected to methods of treating an aqueous solution having one or morecontaminants therein to help remove or reduce the amounts ofcontaminants. In various embodiments, the method includes providing anaqueous solution comprising at least one contaminant selected from thegroup consisting of an organism, an organic chemical, an inorganicchemical, and combinations thereof and exposing the aqueous solution tophotoelectrocatalytic oxidization.

In one example of an application of the device described herein, thedevice uses photoelectrocatalysis as a treatment method for frackingfluid. While typically described herein as reducing levels of orremoving contaminants from fracking fluid, it should be understood byone skilled in the art that photoelectrocatalysis of other contaminantscan be performed similarly using the device (e.g., photoelectrocatalyticoxidation or PECO device).

In various embodiments, one or more contaminants are oxidized by a freeradical produced by a photoelectrode, and wherein one or morecontaminants are altered electrochemically (e.g., byelectroprecipitation or electrocoagulation). In various embodiments, oneor more contaminants are oxidized by a chlorine atom produced by aphotoelectrode. In various embodiments, one or more contaminants arealtered electrochemically (e.g., by electroprecipitation orelectrocoagulation).

In one or more embodiments, the apparatus and methods utilizephotoelectrocatalytic oxidation, whereby a photocatalytic anode iscombined with a counterelectrode to form an electrolytic cell. Invarious embodiments, when the instant anode is illuminated by UV light,its surface becomes highly oxidative. By controlling variablesincluding, without limitation, chloride concentration, light intensity,pH and applied potential, the irradiated and biased TiO₂ compositephotoelectrode may selectively oxidize contaminants that come intocontact with the surface, forming less harmful gas or other compounds.In various embodiments, application of a potential to the photoelectrodeprovides further control over the oxidation products. Periodic orintermittent reversal of the potential may help further remove or reducethe amount of contaminants.

The foregoing apparatus and method provides various advantages. Thedevice may be provided in a portable container (e.g., a mobile trailer),permitting on-site water or fluid decontamination. Further, the deviceis modular in design and can be easily combined with other devices asneeded. The device is also easy to fabricate and includes electricalconnections which are easy to make. The cathode may be positioned behindthe anode and away from the scouring action of water flow, reducing orlimiting scale accumulation. Additionally, any spacer or separatorprovided between the counterelectrode and photoelectrode reducesshorting caused by contact or proximity of the electrode. These andother advantages are apparent from the foregoing description andassociated Figures.

As utilized herein, the terms “approximately,” “about,” “substantially”,and similar terms are intended to have a broad meaning in harmony withthe common and accepted usage by those of ordinary skill in the art towhich the subject matter of this disclosure pertains. It should beunderstood by those of skill in the art who review this disclosure thatthese terms are intended to allow a description of certain featuresdescribed and claimed without restricting the scope of these features tothe precise numerical ranges provided. Accordingly, these terms shouldbe interpreted as indicating that insubstantial or inconsequentialmodifications or alterations of the subject matter described and claimedare considered to be within the scope of the invention as recited in theappended claims.

It should be noted that references to relative positions (e.g., “top”and “bottom”) in this description are merely used to identify variouselements as are oriented in the Figures. It should be recognized thatthe orientation of particular components may vary greatly depending onthe application in which they are used.

For the purpose of this disclosure, the term “coupled” means the joiningof two members directly or indirectly to one another. Such joining maybe stationary in nature or moveable in nature. Such joining may beachieved with the two members or the two members and any additionalintermediate members being integrally formed as a single unitary bodywith one another or with the two members or the two members and anyadditional intermediate members being attached to one another. Suchjoining may be permanent in nature or may be removable or releasable innature.

It is also important to note that the construction and arrangement ofthe system, methods, and devices as shown in the various examples ofembodiments is illustrative only. Although only a few embodiments havebeen described in detail in this disclosure, those skilled in the artwho review this disclosure will readily appreciate that manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter recited. For example,elements shown as integrally formed may be constructed of multiple partsor elements show as multiple parts may be integrally formed, theoperation of the interfaces may be reversed or otherwise varied, thelength or width of the structures and/or members or connector or otherelements of the system may be varied, the nature or number of adjustmentpositions provided between the elements may be varied (e.g., byvariations in the number of engagement slots or size of the engagementslots or type of engagement). The order or sequence of any process ormethod steps may be varied or re-sequenced according to alternativeembodiments. Other substitutions, modifications, changes and omissionsmay be made in the design, operating conditions and arrangement of thevarious examples of embodiments without departing from the spirit orscope of the present inventions.

While this invention has been described in conjunction with the examplesof embodiments outlined above, various alternatives, modifications,variations, improvements and/or substantial equivalents, whether knownor that are or may be presently foreseen, may become apparent to thosehaving at least ordinary skill in the art. Accordingly, the examples ofembodiments of the invention, as set forth above, are intended to beillustrative, not limiting. Various changes may be made withoutdeparting from the spirit or scope of the invention. Therefore, theinvention is intended to embrace all known or earlier developedalternatives, modifications, variations, improvements and/or substantialequivalents.

We claim:
 1. An assembly for removing or reducing the level ofcontaminants in a solution comprising: a first light source having alongitudinal axis; a plurality of second light sources provided about aline concentric to the longitudinal axis of the first light source; afirst photoelectrode provided between the first light source andplurality of second light sources; a second photoelectrode providedaround the second light sources; at least one counterelectrode providedbetween the first photoelectrode and the second photoelectrode; whereinthe first photoelectrode and second photoelectrode each comprise aprimarily titanium foil support with a layer of titanium dioxideprovided on at least one surface the photoelectrode; and wherein thefirst photoelectrode, second photoelectrode and at least onecounterelectrode are each coupled to a respective terminal adapted to beelectrically coupled to a power supply.
 2. The assembly of claim 1,further comprising a bulkhead coupled to the at least onecounterelectrode and first and second light sources.
 3. The assembly ofclaim 1, wherein there at least three second light sources providedabout a line concentric to the longitudinal axis of the first lightsource.
 4. The assembly of claim 1, wherein there are five second lightsources provided about a line concentric to the longitudinal axis of thefirst light source.
 5. The assembly of claim 1, wherein there are sixsecond light sources provided about a line concentric to thelongitudinal axis of the first light source.
 6. The assembly of claim 1,wherein the first and second light sources comprise a light sleeve andend cap and wherein the end cap is removeably coupled to the bulkheadmember.
 7. The assembly of claim 1, further comprising a spacer, thespacer comprising a peripheral concentric portion coupled to an axialconcentric portion by at least one divider.
 8. An assembly for removingor reducing the level of contaminants in a solution comprising: aplurality of light sources spaced in a radial array between a firstphotoelectrode and a second photoelectrode; at least onecounterelectrode provided between the first photoelectrode and thesecond photoelectrode; wherein the first photoelectrode and secondphotoelectrode each comprise a primarily titanium foil support with alayer of titanium dioxide provided on at least one surface thephotoelectrode; and wherein the first photoelectrode, secondphotoelectrode and at least one counterelectrode are each coupled to arespective terminal adapted to be electrically coupled to a powersupply.
 9. The assembly of claim 8, further comprising a longitudinalaxis and a light source provided about the longitudinal axis.
 10. Theassembly of claim 8, further comprising a bulkhead coupled to the atleast one counterelectrode and the light sources.
 11. The assembly ofclaim 8, wherein there are more than three light sources spaced in aradial array between a first photoelectrode and a second photoelectrode;12. The assembly of claim 8, wherein there are five light sources spacedin a radial array between a first photoelectrode and a secondphotoelectrode;
 13. The assembly of claim 8, wherein there are six lightsources spaced in a radial array between a first photoelectrode and asecond photoelectrode;
 14. The assembly of claim 8, wherein the firstand second light sources comprise a light sleeve and end cap and whereinthe end cap is removeably coupled to the bulkhead member.
 15. Theassembly of claim 8, further comprising a spacer provided between thefirst photoelectrode and the second photoelectrode, the spacercomprising a peripheral concentric portion coupled to an axialconcentric portion by at least one divider.
 16. An apparatus forremoving or reducing the level of contaminants in a solution comprising:a housing member having first opposing end and a second opposing end andat least partially defining a cavity having a cavity wall and a cavitylongitudinal axis; a first light source provided within the cavity; afirst photoelectrode provided between the first light source and thecavity wall; a second photoelectrode provided between the firstphotoelectrode and the cavity wall; a plurality of second light sourcesprovided between the first photoelectrode and the second photoelectrode;a counterelectrode provided between the first photoelectrode and thecavity wall; wherein the first photoelectrode and second photoelectrodeeach comprises a primarily titanium foil support with a layer oftitanium dioxide provided on at least one surface the photoelectrode;and wherein the first photoelectrode, second photoelectrode andcounterelectrode are each coupled to a respective terminal adapted to beelectrically coupled to a power supply.
 17. The apparatus of claim 15,wherein the first light source is provided about the cavity longitudinalaxis.
 18. The apparatus of claim 15, wherein the second light sourcesare spaced symmetrically around the cavity longitudinal axis.
 19. Theapparatus of claim 15, wherein the first photoelectrode is providedaround the first light source.
 20. The apparatus of claim 15, whereinthe second photoelectrode is provided around the plurality of secondlight sources.